#include <stdio.h>
#include "mystdio.h"
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>


const char *toString(int flag)
{
    if(flag & NONE_FLUSH) return "None";
    else if(flag & LINE_FLUSH) return "Line";
    else if(flag & FULL_FLUSH) return "FULL";
    return "Unknow";
}

void DebugPrint(myFILE *fp)
{
    printf("outbufer: %s\n", fp->outbuffer);
    printf("fd: %d\n", fp->fileno);
    printf("pos: %d\n", fp->pos);
    printf("cap: %d\n", fp->cap);
    printf("flush_mode: %s\n", toString(fp->flush_mode));
}


myFILE* my_fopen(const char* pathname,const char* mode)
{
  int flag = 0;
  if(strcmp(mode,"r") == 0)
  {
    flag |= O_RDONLY;
  }
  else if(strcmp(mode,"w") == 0)
  {
    flag |= (O_TRUNC |O_WRONLY | O_CREAT);
  }
  else if(strcmp(mode,"a") == 0)
  {
    flag |= (O_WRONLY | O_CREAT | O_APPEND);
  }
  else
  {
    return NULL;
  }

  int fd = 0;
  if(flag & O_RDONLY)
  {
    umask(0);
    fd = open(pathname,flag,0666);
  }
  else
  {
    fd = open(pathname,flag,0666);
  }

  if(fd < 0) return NULL;

  myFILE* fp = (myFILE*)malloc(sizeof(myFILE));
  if(fp == NULL) return NULL;
  fp->fileno = fd;
  fp->cap = SIZE;
  fp->pos = 0;
  fp->flush_mode = LINE_FLUSH;

  return fp;
}

void my_fflush(myFILE* fp)
{
  if(fp->pos == 0) return;
  write(fp->fileno,fp->outbuffer,fp->pos);
  fp->pos = 0;
}


int my_fwrite(myFILE* fp,const char* s,int size)
{
  memcpy(fp->outbuffer+fp->pos,s,size);
  fp->pos+=size;

  if((fp->flush_mode & LITTLE_ENDIAN) && fp->outbuffer[fp->pos -1] == '\n')
  {
    my_fflush(fp);
  }
  else if((fp->flush_mode & FULL_FLUSH) && fp->pos == fp->cap)
  {
    my_fflush(fp);
  }

  return size;
}

int my_fclose(myFILE* fp)
{
  my_fflush(fp);
  close(fp->fileno);
  free(fp);
}
